This invention relates to a porting system for internal combustion engines and more particularly to an improved porting arrangement for engines having plural intake ports for each chamber.
It is well known that the specific output of an internal combustion engine can generally be improved by providing plural intake ports for each chamber of the engine. By using plural ports, it is possible to obtain higher rotational speeds, greater inlet area and greater specific output. However, the use of such plural ports to achieve high performance can seriously and adversely affect the low speed running of the engine. Because of the large effective port area, the gas velocities at low speeds become extremely slow and poor fuel economy and other poor running results.
It is, therefore, a principal object of this invention to provide an improved porting arrangement for internal combustion engines that permits the achievement of high specific outputs and yet which will insure good low speed running.
It is a further object of this invention to provide an improved porting system for internal combustion engines that assists the performance throughout the engine speed and load ranges.
In accordance with a feature of the invention, a staged induction porting arrangement is utilized for the chambers of an internal combustion engine. The engine is provided with plural intake ports and one port is employed for primarily serving the low speed running while other ports are employed for assisting high speed performance. Separate charge formers are employed for the low and high speed ports. Although this arrangement is particularly effective, when employed with multiple chamber internal combustion engines, it can become rather complicated.
It is, therefore, a still further object of this invention to provide an improved porting and induction system for multiple chamber engines that will achieve the aforenoted results while still maintaining a relatively uncomplicated construction.